Synthesis and investigation of tetraaminophthalocyanines for electrocatalytic reduction reaction of carbon dioxide

Abstract

In this work, synthesis and investigation on homogeneous catalytic activities for electrochemical reduction (ECR) of carbon dioxide (CO₂) of amino-functionalized Co(II)-, Ni(II)-, and Cu(II)- phthalocyanines were described. Current enhancement under CO₂-saturated condition observed by cyclic voltammetry indicated involvement of all complexes in the ECR of CO₂. Chronoamperometry applying potential of ‒1.6 V vs. Ag/AgCl QRE for 2 h, followed by product analysis by gas chromatography showed that amino-functionalized Co(II)-, Ni(II)-, and Cu(II)-phthalocyanines yielded hydrogen gas (H₂) with %Faradaic efficiency (%FE) of 32%, 35% and 39%, respectively. However, only amino-functionalized Co(II)- and Ni(II)- phthalocyanines yielded carbon monoxide (CO) with %FE of 1.6% and 0.2%, respectively. The results indicated that it is promising to further develop Co(II)-phthalocyanine-based electrocatalytic system for the production of CO while the Cu(II)-phthalocyanine-based one seems to be suitable for H₂ evolution. Keywords: